The mission of the Fluorescence Cytometry (FC) Core Facility is to provide investigators with state-of-the art technology in a cost-effective manner to aid in understanding cellular processes involved in environmental health challenges. Understanding the processes at this level enables researchers to formulate and test theories as to how environmental factors affect health. The Core is home to instruments that use fluorescent markers and/or monoclonal antibodies to investigate cellular processes. The BD FACSAria is a state-of-the art flow cytometer and high-speed cell sorter. The three-laser, ten filter-set configuration allows the identification of multiple molecular signals to be analyzed simultaneously. Further, the instrument has capabilities of precise sorting of subpopulations of interest for further investigation. The BD FACSCalibur is a 1-laser, 3-detector flow cytometer that provides basic cell analysis in 5 parameters. The CompuCyte iCys Laser Scanning Cytometer (LSC) offers similar detection of molecular signals as in flow Cytometry, the difference being that the sample is fixed on a microscope slide or cell culture plates, rather than in a fluid suspension. This allows more types of tissues to be analyzed and permits visualization of tissues and individual cells. The Miltenyi Biotec autoMacs cell sorter purifies subpopulations by magnetic bead separation for further investigation. The Luminex 100 analyzes addressable laser bead arrays for capture and detection of multiple analytes in small samples. The Zeiss Fluorescence Microscope and Imaging System is used to visualize and capture images of fluorescently tagged cells. In addition to providing reliable, well-maintained instrumentation, the Core offers scientific expertise in experiment design and analysis. The complexity of the technology of the instruments, reagents and protocols require a thorough understanding and training. Having a Core Director and Staff Scientist available to oversee projects ensures reliable and reproducible results using accepted methodologies. The combination of available instrumentation and expertise puts the researchers at CEHS as well as other investigators at the University of Montana at a competitive advantage in publishing and obtaining extramural funding.